Strategies for Enhancing Vascularization of Biomaterial‐Based Scaffold in Bone Regeneration

Abstract

Despite the recent advances in reconstructive orthopedics; fracture union is a challenge to bone regeneration. Concurrent angiogenesis is a complex process governed by events, delicately entwined with osteogenesis. However, poorly perfused scaffolds have lower success rates; necessitating the need for a better vascular component, which is important for the delivery of nutrients, oxygen, waste elimination, recruitment of cells for optimal bone repair. This review highlights the latest strategies to promote biomaterial-based scaffold vascularization by incorporation of cells, growth factors, inorganic ions, etc. into natural or synthetic polymers, ceramic materials, or composites of organic and inorganic compounds. Furthermore, it emphasizes structural modifications, biophysical stimuli, and natural molecules to fabricate scaffolds aiding the genesis of dense vascularization following their implantation to manifest a compatible regenerative microenvironment without graft rejection.

Pro-angiogenic photo-crosslinked silk fibroin hydrogel: a potential candidate for repairing alveolar bone defects

“…Tissue engineering commonly use stem cells, growth factors, and biomaterials to promote vessel formation. 6 - 8 However, compared with stem cells, cell products, and growth factors, biomaterials show easier quality control and scalable production. 21 Besides, the biomaterial is a crucial component for engineered bone scaffolds, which provide mechanical supports and porous structures for cell migration.…”

“… 4 - 6 Without adequate vascularization, bone regeneration can be slowed down or even halted altogether. 7 , 8 This can lead to complications such as delayed healing, non-union, or even the development of bone necrosis. Thus, strategies enhancing vascularization could be promising treatments for alveolar bone defects.…”

Recent trends in bone tissue engineering: a review of materials, methods, and structures

“…Osteoprogenitor cells, which originate from MSCs and differentiate into osteoblasts, transfer to the endosteal and periosteal surface of the bone as well as the inner surface of the Haversian canals [51]. Various signals, such as releasing cytokines like TGF-β and BMPs, are sent by MSCs that lead to osteoprogenitor cell derivation and bone formation [53]. In addition, the implanted exogenous MSCs in the scaffold could engage the host's osteoprogenitor cells to develop new bone and expand the perspectives for BTE [54].…”

Exogeneous metal ions as therapeutic agents in cardiovascular disease and their delivery strategies

“…Nevertheless, their hydrophilicity may lead to low encapsulation efficiency of hydrophobic bioactive molecules and drugs, and their highly porous structure may lead to cargo leakage during transportation [ 191 ]. Solid scaffolds play an important role in cartilage repair, bone tissue engineering, heart repair and drug delivery [ 192 ]. They have good mechanical strength that the aforementioned carriers do not possess, and their interactions with cells are also conducive to stimulating the formation of functional tissues [ 193 , 194 ].…”